type MapType<T> = {
    [Key in keyof T as `${Key & string}${Key & string}`]: [T[Key], T[Key]]
}

type res = MapType<{a: 1}>

type objType = ({c: string} | {a: string}) & {c: string, d: string}

const obj: objType = {a: 'a', c: 'c', d: 'd'}

type strType = string | number | boolean

type fixType = strType & string

export {}